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Human serum Zn-α2-glycoprotein in amniotic fluid
107
Clinica Chimica Acta, 85 (1978) 107-110 @ Elsevier/North-Holland Biomedical Press
CCA 9165
HUMAN SERUM Zn-cu,-GLYCOPROTEIN
M. JIRKA
a+*, P. BLANICK?
a, J. GRAJER
IN AMNIOTIC
a, A. ZWINGER
FLUID
b and J.E. JIRASEK
b
a Research Institute of Child Development, Faculty of Pediatrics, Charles University, PragueMotol, and b Institute for the Care of Mother and Child, Prague-Podoli (Czechoslovakia) (Received
September
9th, 1977)
summary
Human serum Zn-cY2-glycoprotein (Zn-u,-GP) was found to be present in the amniotic fluid in the mean concentration of 0.98 + 0.40 mg/lOO ml, which represents about one-tenth of its concentration in the maternal serum (9.65 5 1.18 mg/lOO ml). Its concentration in the amniotic fluid was proportional to the amniotic fluid total protein and very approximately to the maternal serum Zniu*-GP. The relationship between the maternal serum Zn-az-GP and the maternal serum total protein as well as between the amniotic fluid total protein and the maternal serum total protein was found to be not significant. The amniotic fluid Zn-02-GP as well as the amniotic fluid total protein showed some increase during gestation to reach the highest values at the end of the second trimester. At present both the origin and significance of the amniotic fluid Zn-ez-GP are not known.
Introduction The biological function of Zn+z-glycoprotein (Zn-cu,-GP) which is one of the low molecular weight (3 S) crz-glycoproteins of normal human plasma [l] is not known. A physiological fetal and early newborn hypo-Zn-a*-glycoproteinaemia exists (2.5 c 1.8 mg/lOO ml-4.8 + 1.6 mg/lOO ml in comparison with 8.9 ? 2.2 mg/lOO ml-lo.4 + 4.0 mg/lOO ml in the postnatal age) [2]. A pathological hyper-Zn**-glycoproteinaemia has been found to be associated with renal pathology probably as a result of a defect in the metabolic function of the kidney [3,4]. A relatively high Zn-cu2-GP content (when related to total protein) was found to be present ip sweat, saliva, and urine of healthy individuals; its presence was also reported in kidney tissue extract [ 561. * To whom correspondence should be addressed.
During the prenatal period a progressive increase of the serum Z~N~-GP level in the fetal serum was found [Z]. Therefare data pertaining to amniotic ffuid seemed to be worth studying. Materials and methods 96 samples of maternal serum and amniotic fluid obtained by amniocentesis performed for the reasons of prenatal diagnosis of genetic disorders (between the 11th and 38th week of menstrual age) were examined. Zn-at*-GP was estimated by eiectrophoresis in antibody-containing agarose gel with p~an~nlet~c evaluation of antigen-antibody precipitation peak area (standard error + 8.2%) using purified human serum Zn*z-GP preparation as a control (gift from Dr. Karl Schmid, Boston University ,Medical School, Boston, Mass.) [Z]. The total protein was determined by the biuret method with pure human serum albumin preparation as a control (Dade Human Protein Standard, Dade Division, Miami, Florida) using Beckman spectrophotometer Acta CV (standard error t 1.9%). Results The mean Zna,-GP concentration in the amniotic fluid from the 11th to the 38th week was 0.98 i- 0.40 mg/lOO ml and that in the maternal serum 9.65 5 1.18 mg/lOO ml (N = 96). The amniotic fluid Zne2-GP concentration was very approximately proportional to the maternal serum Zn-cuz-GP concentration (N = 96, r = 0.275, p < 0.01, Fig. 1). The mean total protein concentration in our samples of amniotic fluid was 0.54 F 0.16 g/100 ml (N = $2) and that in the maternal serum 7.38 t 0.70 g/
.
1 /
1IS_
r
. __..*”
.---. . *. .
.-•a.- f.
z
)..
_ -
___---
_.
___.--___---__--
..-i- ---
__.--
*/---
__a
10
5
_“*I--
15
MS~n_~x__Cp~mg~lOOml~ Fig.
1. The
0.383.
maternal
I‘ = 0.255,
serum
P < 0.01.
(&IS> and
amniotic f&id (AF) Zn-cl~-GP concentration.
J’ = 0.081
+ 0.093~
t
109
I 0.2
1.0
06 AfTP
(g
100ml
)
Fig. 2. The amniotic fluid total protein (AFTP) and Zn_cu2-GP concentration. Y = 0.122 0.218, r = 0.733, P < 0.001.
+ 1.45 X 10m3x t
100 ml (N = 69). There was no significant relation between the total protein in the amniotic fluid and in the maternal serum (N = 66). In the amniotic fluid, the Zna,-GP was proportions to the total protein (N = 82, r = 0.733, p < 0.001, Fig. 2). In the maternal serum, their relationship was not significant (N = 69). In amniotic fluid in the range from 11th to the 26th week, there was some increase in the Zn-ol,-GP (N = 92, r = 0.288, p < 0.01) as well as the total protein (N = 78, r = 0.234, p < 0.05). After the 26th week, a decrease of the amniotic fluid total protein was observed while that of the amniotic fluid Zn-cu*-GP did not reach statistical significance (N = 4).
TABLE I Zn*z-GLYCOPROTEIN (Zn-crz-GP) AND TOTAL PROTEIN (TP) AFTER REPEATED AMNIOCENTESIS IN FIVE SUBJECTS (l-5) Subject
1
2 3 4 5 Mean S.D. p Zn-o12-GP pTP
LEVELS
IN AMNIOTIC
First amniocentesis
Second amniocentesis
(menstrual week)
(menstruai week) Zn-orz-GP (mg/lOO ml)
TP
0.60 0.55 0.68 0.49 0.39
1.10 1.24 1.12 1.49 0.89
0.64 0.67 0.68 0.85 0.48
0.54 0.11
1.17 0.22
Znq-GP (mg/lOO ml)
TP
0.80 0.80 0.78 0.80 0.54 0.14 0.11
(20) (20) (18) (18) (19)
FLUID
@/IO0
ml)
(23) (26) (21) (23) (23)
(g/100
0.66 0.13
ml)
En strbjects in which amniocentesis was repeated after 3 to 6 weeks, between the week 18 and 26 respec~iv~l~~ a significant increase in the amniotic fluid Zn-cu,-GP (from 0.74 i 0.11 to 1.17 5 0.14 mg/lOO ml, IV - 5, p c’. 0.01) was observed (in contrast to the amniotic fluid total protein). The data are shown in Table I.
Discussion We found that Zn-oz&P is present in amniotic fluid in a retativefy higher concent~ti~~ fwben related to total protein) than chat in maternal serum. Its ~0~~~~~~~~~~~ shows some trend to inerase d~~~~ g&&ion. The presenct? of Zn-tu2-GPin ~rn~~~~~~ fluid could have been expected since it bad been found in other biofogicti fluids as well f2,5,6]. At present we ‘nave no data with regard to both its origin and its significance.
Acknowledgements Our thanks assistance.
are due to Mrs. R. Hartmanovri
from our laboratory
1975, Absa. Free Cummun.. No. 583 4 Jirka, J., Buridnovii, B., Jirka, M. and Blanick~, P. (1976) Biomed. Express 26.246 5 Pnortmans, J.R. and Schmid, K. (1,968) J. I&. Clin. Med. 71,807 6 Jirka. M. and Blanickjr, P. (1973) Gas, Lik. Ces. 112, 1606 (in Czech)
for valuable
Clinica Chimica Acta, 85 (1978) 107-110 @ Elsevier/North-Holland Biomedical Press
CCA 9165
HUMAN SERUM Zn-cu,-GLYCOPROTEIN
M. JIRKA
a+*, P. BLANICK?
a, J. GRAJER
IN AMNIOTIC
a, A. ZWINGER
FLUID
b and J.E. JIRASEK
b
a Research Institute of Child Development, Faculty of Pediatrics, Charles University, PragueMotol, and b Institute for the Care of Mother and Child, Prague-Podoli (Czechoslovakia) (Received
September
9th, 1977)
summary
Human serum Zn-cY2-glycoprotein (Zn-u,-GP) was found to be present in the amniotic fluid in the mean concentration of 0.98 + 0.40 mg/lOO ml, which represents about one-tenth of its concentration in the maternal serum (9.65 5 1.18 mg/lOO ml). Its concentration in the amniotic fluid was proportional to the amniotic fluid total protein and very approximately to the maternal serum Zniu*-GP. The relationship between the maternal serum Zn-az-GP and the maternal serum total protein as well as between the amniotic fluid total protein and the maternal serum total protein was found to be not significant. The amniotic fluid Zn-02-GP as well as the amniotic fluid total protein showed some increase during gestation to reach the highest values at the end of the second trimester. At present both the origin and significance of the amniotic fluid Zn-ez-GP are not known.
Introduction The biological function of Zn+z-glycoprotein (Zn-cu,-GP) which is one of the low molecular weight (3 S) crz-glycoproteins of normal human plasma [l] is not known. A physiological fetal and early newborn hypo-Zn-a*-glycoproteinaemia exists (2.5 c 1.8 mg/lOO ml-4.8 + 1.6 mg/lOO ml in comparison with 8.9 ? 2.2 mg/lOO ml-lo.4 + 4.0 mg/lOO ml in the postnatal age) [2]. A pathological hyper-Zn**-glycoproteinaemia has been found to be associated with renal pathology probably as a result of a defect in the metabolic function of the kidney [3,4]. A relatively high Zn-cu2-GP content (when related to total protein) was found to be present ip sweat, saliva, and urine of healthy individuals; its presence was also reported in kidney tissue extract [ 561. * To whom correspondence should be addressed.
During the prenatal period a progressive increase of the serum Z~N~-GP level in the fetal serum was found [Z]. Therefare data pertaining to amniotic ffuid seemed to be worth studying. Materials and methods 96 samples of maternal serum and amniotic fluid obtained by amniocentesis performed for the reasons of prenatal diagnosis of genetic disorders (between the 11th and 38th week of menstrual age) were examined. Zn-at*-GP was estimated by eiectrophoresis in antibody-containing agarose gel with p~an~nlet~c evaluation of antigen-antibody precipitation peak area (standard error + 8.2%) using purified human serum Zn*z-GP preparation as a control (gift from Dr. Karl Schmid, Boston University ,Medical School, Boston, Mass.) [Z]. The total protein was determined by the biuret method with pure human serum albumin preparation as a control (Dade Human Protein Standard, Dade Division, Miami, Florida) using Beckman spectrophotometer Acta CV (standard error t 1.9%). Results The mean Zna,-GP concentration in the amniotic fluid from the 11th to the 38th week was 0.98 i- 0.40 mg/lOO ml and that in the maternal serum 9.65 5 1.18 mg/lOO ml (N = 96). The amniotic fluid Zne2-GP concentration was very approximately proportional to the maternal serum Zn-cuz-GP concentration (N = 96, r = 0.275, p < 0.01, Fig. 1). The mean total protein concentration in our samples of amniotic fluid was 0.54 F 0.16 g/100 ml (N = $2) and that in the maternal serum 7.38 t 0.70 g/
.
1 /
1IS_
r
. __..*”
.---. . *. .
.-•a.- f.
z
)..
_ -
___---
_.
___.--___---__--
..-i- ---
__.--
*/---
__a
10
5
_“*I--
15
MS~n_~x__Cp~mg~lOOml~ Fig.
1. The
0.383.
maternal
I‘ = 0.255,
serum
P < 0.01.
(&IS> and
amniotic f&id (AF) Zn-cl~-GP concentration.
J’ = 0.081
+ 0.093~
t
109
I 0.2
1.0
06 AfTP
(g
100ml
)
Fig. 2. The amniotic fluid total protein (AFTP) and Zn_cu2-GP concentration. Y = 0.122 0.218, r = 0.733, P < 0.001.
+ 1.45 X 10m3x t
100 ml (N = 69). There was no significant relation between the total protein in the amniotic fluid and in the maternal serum (N = 66). In the amniotic fluid, the Zna,-GP was proportions to the total protein (N = 82, r = 0.733, p < 0.001, Fig. 2). In the maternal serum, their relationship was not significant (N = 69). In amniotic fluid in the range from 11th to the 26th week, there was some increase in the Zn-ol,-GP (N = 92, r = 0.288, p < 0.01) as well as the total protein (N = 78, r = 0.234, p < 0.05). After the 26th week, a decrease of the amniotic fluid total protein was observed while that of the amniotic fluid Zn-cu*-GP did not reach statistical significance (N = 4).
TABLE I Zn*z-GLYCOPROTEIN (Zn-crz-GP) AND TOTAL PROTEIN (TP) AFTER REPEATED AMNIOCENTESIS IN FIVE SUBJECTS (l-5) Subject
1
2 3 4 5 Mean S.D. p Zn-o12-GP pTP
LEVELS
IN AMNIOTIC
First amniocentesis
Second amniocentesis
(menstrual week)
(menstruai week) Zn-orz-GP (mg/lOO ml)
TP
0.60 0.55 0.68 0.49 0.39
1.10 1.24 1.12 1.49 0.89
0.64 0.67 0.68 0.85 0.48
0.54 0.11
1.17 0.22
Znq-GP (mg/lOO ml)
TP
0.80 0.80 0.78 0.80 0.54 0.14 0.11
(20) (20) (18) (18) (19)
FLUID
@/IO0
ml)
(23) (26) (21) (23) (23)
(g/100
0.66 0.13
ml)
En strbjects in which amniocentesis was repeated after 3 to 6 weeks, between the week 18 and 26 respec~iv~l~~ a significant increase in the amniotic fluid Zn-cu,-GP (from 0.74 i 0.11 to 1.17 5 0.14 mg/lOO ml, IV - 5, p c’. 0.01) was observed (in contrast to the amniotic fluid total protein). The data are shown in Table I.
Discussion We found that Zn-oz&P is present in amniotic fluid in a retativefy higher concent~ti~~ fwben related to total protein) than chat in maternal serum. Its ~0~~~~~~~~~~~ shows some trend to inerase d~~~~ g&&ion. The presenct? of Zn-tu2-GPin ~rn~~~~~~ fluid could have been expected since it bad been found in other biofogicti fluids as well f2,5,6]. At present we ‘nave no data with regard to both its origin and its significance.
Acknowledgements Our thanks assistance.
are due to Mrs. R. Hartmanovri
from our laboratory
1975, Absa. Free Cummun.. No. 583 4 Jirka, J., Buridnovii, B., Jirka, M. and Blanick~, P. (1976) Biomed. Express 26.246 5 Pnortmans, J.R. and Schmid, K. (1,968) J. I&. Clin. Med. 71,807 6 Jirka. M. and Blanickjr, P. (1973) Gas, Lik. Ces. 112, 1606 (in Czech)
for valuable